A183328 T(n,k)=Number of nXk binary arrays with each 1 adjacent to exactly two other 1s.

1, 1, 1, 1, 2, 1, 1, 3, 3, 1, 1, 4, 6, 4, 1, 1, 6, 10, 10, 6, 1, 1, 9, 19, 27, 19, 9, 1, 1, 13, 37, 72, 72, 37, 13, 1, 1, 19, 69, 179, 289, 179, 69, 19, 1, 1, 28, 129, 447, 996, 996, 447, 129, 28, 1, 1, 41, 244, 1139, 3325, 4740, 3325, 1139, 244, 41, 1, 1, 60, 460, 2912, 11415, 21259

Offset: 1

Author

R. H. Hardin Jan 03 2011

Keywords

• nonn
• tabl

Comments

Table starts

.1..1...1....1......1.......1........1.........1..........1...........1

.1..2...3....4......6.......9.......13........19.........28..........41

.1..3...6...10.....19......37.......69.......129........244.........460

.1..4..10...27.....72.....179......447......1139.......2912........7434

.1..6..19...72....289.....996.....3325.....11415......39720......138689

.1..9..37..179....996....4740....21259.....96524.....443793.....2054180

.1.13..69..447...3325...21259...128371....770542....4639132....28160294

.1.19.129.1139..11415...96524...770542...6115158...48449560...386449543

.1.28.244.2912..39720..443793..4639132..48449560..505971397..5319953708

.1.41.460.7434.138689.2054180.28160294.386449543.5319953708.73890230419

Examples

			Some solutions for 7X6
..0..1..1..1..1..1....0..0..1..1..1..0....0..0..1..1..1..1....0..0..1..1..1..0
..0..1..0..0..0..1....0..1..1..0..1..0....1..1..1..0..0..1....0..0..1..0..1..0
..0..1..0..1..1..1....1..1..0..0..1..1....1..0..0..0..0..1....1..1..1..0..1..1
..0..1..0..1..0..0....1..0..0..0..0..1....1..1..0..0..0..1....1..0..0..0..0..1
..1..1..0..1..1..0....1..0..0..0..1..1....0..1..0..0..0..1....1..1..0..0..0..1
..1..0..0..0..1..0....1..0..1..1..1..0....0..1..1..1..0..1....0..1..1..0..0..1
..1..1..1..1..1..0....1..1..1..0..0..0....0..0..0..1..1..1....0..0..1..1..1..1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..391

Crossrefs

Column 2 is A000930(n+1)